Caching table definitions to improve performance. Closes #72

Author: stefanmielke

DataCore.Test/DataCore.Test.csproj

@@ -89,6 +89,7 @@
     <Compile Include="Models\TestNullableProperty.cs" />
     <Compile Include="Models\TestOther.cs" />
     <Compile Include="Models\TestOverride.cs" />
+    <Compile Include="PerformanceTest.cs" />
     <Compile Include="QueryTestGroupBy.cs" />
     <Compile Include="QueryTestHaving.cs" />
     <Compile Include="QueryTestJoins.cs" />

DataCore.Test/PerformanceTest.cs

@@ -0,0 +1,47 @@
+using DataCore.Test.Models;
+using NUnit.Framework;
+
+namespace DataCore.Test
+{
+    [TestFixture]
+    public class PerformanceTest
+    {
+        [Test]
+        public void TimedSelect()
+        {
+            using (var connection = TestHelper.GetConnectionFor(TestHelper.DatabaseType.Sqlite, "Data Source=:memory:"))
+            {
+                var db = TestHelper.GetDatabaseFor(TestHelper.DatabaseType.Sqlite, connection);
+
+                db.CreateTableIfNotExists<TestClass>();
+                db.Insert(TestHelper.GetNewTestClass());
+
+                for (int i = 0; i < 100000; i++)
+                {
+                    db.SelectById<TestClass>(1);
+                }
+
+                connection.Close();
+            }
+        }
+
+        [Test]
+        public void TimedSelectWhere()
+        {
+            using (var connection = TestHelper.GetConnectionFor(TestHelper.DatabaseType.Sqlite, "Data Source=:memory:"))
+            {
+                var db = TestHelper.GetDatabaseFor(TestHelper.DatabaseType.Sqlite, connection);
+
+                db.CreateTableIfNotExists<TestClass>();
+                db.Insert(TestHelper.GetNewTestClass());
+
+                for (int i = 0; i < 100000; i++)
+                {
+                    db.Select<TestClass>(t => t.Id == 1);
+                }
+
+                connection.Close();
+            }
+        }
+    }
+}

DataCore/TableDefinition.cs

@@ -7,17 +7,31 @@
 
 namespace DataCore
 {
-    public class TableDefinition
+    public sealed class TableDefinition
     {
-        public string Name { get; set; }
-        public FieldDefinition IdField { get; set; }
-        public List<FieldDefinition> Fields { get; set; }
+        private static readonly Dictionary<Type, TableDefinition> Definitions = new Dictionary<Type, TableDefinition>();
+
+        public string Name { get; }
+        public FieldDefinition IdField { get; }
+        public List<FieldDefinition> Fields { get; }
 
         public TableDefinition(Type type)
         {
+            if (Definitions.ContainsKey(type))
+            {
+                var definition = Definitions[type];
+                Name = definition.Name;
+                IdField = definition.IdField;
+                Fields = definition.Fields;
+
+                return;
+            }
+
             Name = GetTableName(type);
             IdField = GetIdFieldForType(type);
             Fields = GetPropertiesForType(type).Select(GetFieldForProperty).ToList();
+
+            Definitions.Add(type, this);
         }
 
         private IEnumerable<PropertyInfo> GetPropertiesForType(Type type)